Dr. Jaykumar R. Thumar, MD, MBBS
Hematology & Oncology (Hematology & Oncology Physician)
- Medicare participating
At a glance
- Years since graduation
- 24
- In the NPI registry since
- 2007
- Medicare patients seen, 2024
- 191
Licensed in Connecticut since 2002, according to the Connecticut Department of Public Health. We show license dates only for the states that publish them in bulk; see which states do. For other states, check the state medical board.
The NPI date is when this clinician registered for a National Provider Identifier, the billing number used on health claims. It is not a license, graduation or board-certification date. NPIs were first issued in May 2005 and became required on claims in 2007–2008, so an early date usually means the clinician was already in practice before then. What an NPI is
Education and training
- 2007Registered with an NPI (national billing number; not a license date) — NPIs began in 2005, so practice likely started earlier
Medicare’s Care Compare data doesn’t list this clinician’s medical school. Undergraduate school, residency, fellowship, licensing exams and board certification aren’t in public federal data. Board certification can be confirmed with the certifying board (ABMS member boards for MDs, AOA boards for DOs).
Specialties and state licenses
-
Hematology & Oncology Physician primary
CT license 47107 (first issued 2008; active) -
Hospitalist Physician
CT license 0040328 (first issued 2002; active) -
Internal Medicine Physician
CT license 047107 (first issued 2008; active)
As reported to the NPI registry. To confirm a license is current, check the state medical board.
Where they work
Hospitals
- Hartford Hospital Hartford, CT
- The Hospital of Central Connecticut New Britain, CT
- William W Backus Hospital Norwich, CT
- Windham Community Memorial Hospital Willimantic, CT
Medical groups
- Hartford Hospital (1,044 clinicians)
- The William W Backus Hospital (249 clinicians)
Hospitals this clinician lists with Medicare, and groups they bill Medicare through (Care Compare). Affiliation doesn’t mean they see patients at every location.
Medicare patients and services
- Medicare patients, 2024
- 191
- Services billed
- 744
- Patients’ average age
- 75
| Service | Times | Patients |
|---|---|---|
| Established patient office or other outpatient visit, 30-39 minutes | 121 | 58 |
| Established patient office or other outpatient visit, 40-54 minutes | 63 | 47 |
| New patient office or other outpatient visit, 60-74 minutes | 39 | 39 |
| Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes | 25 | 25 |
| Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | 16 | 12 |
Medicare fee-for-service only. CMS leaves out services billed for fewer than 11 patients. These figures describe a practice’s Medicare work; they aren’t a measure of quality.
Medicare prescriptions
| Drug | Prescriptions |
|---|---|
| Ondansetron Odt (ondansetron) Other prescribers in Enfield, CT | 85 |
| Dexamethasone Other prescribers in Enfield, CT | 79 |
| Metoclopramide Hcl Other prescribers in Enfield, CT | 65 |
| Oxycodone Hcl Other prescribers in Enfield, CT | 61 |
| Prednisone Other prescribers in Enfield, CT | 61 |
| Lorazepam Other prescribers in Enfield, CT | 56 |
| Triamcinolone Acetonide Other prescribers in Enfield, CT | 48 |
| Omeprazole Other prescribers in Enfield, CT | 43 |
| Imatinib Mesylate | 41 |
| Loperamide (loperamide hcl) Other prescribers in Enfield, CT | 39 |
Prescriptions filled under Medicare Part D, including refills. CMS leaves out drugs prescribed fewer than 11 times.
Payments from drug and device companies
In 2025, 4 companies reported 4 payments worth $8,152 in total to this clinician.
| AbbVie Inc. | $2,969 |
|---|---|
| Jazz Pharmaceuticals Inc. | $2,108 |
| AstraZeneca Pharmaceuticals LP | $1,675 |
| Taiho Oncology, Inc. | $1,400 |
| Consulting Fee | $6,044 |
|---|---|
| Compensation for services other than consulting (speaking, faculty) | $2,108 |
What the payments were for
| Company | What it was for | Amount |
|---|---|---|
| AbbVie Inc. Dec 12, 2025 | Consulting Fee | $2,969 |
| Jazz Pharmaceuticals Inc. Aug 11, 2025 | Compensation for services other than consulting (speaking, faculty) ZIIHERA · HEMATOLOGY/ONCOLOGY | $2,108 |
| AstraZeneca Pharmaceuticals LP Jun 2, 2025 | Consulting Fee IMFINZI · Oncology | $1,675 |
| Taiho Oncology, Inc. Aug 1, 2025 | Consulting Fee LONSURF · Oncology | $1,400 |
Each payment as the company reported it, with the products it named. Meals are counted in the totals above but not listed one by one.
From CMS Open Payments. A payment is not evidence of wrongdoing; many are for consulting, teaching or meals. Clinicians can review and dispute their records with CMS.
Industry-funded research
Named as a principal investigator on 6 industry-funded studies in 2025, from 4 companies. The companies reported $217,409 in research payments for these studies, mostly to the institutions running them.
- Atezolizumab and bevacizumab tiragolumab in 1L unresectable hcc pts
Genentech, Inc. - A Phase II study of Atezolizumab with or without Bevacizumab in Patients with HCC
Genentech, Inc. - A Phase 1b Study Evaluating the Safety, Tolerability, Pharmacokinetics, and Efficacy of AMG 193 in Combination With Other Therapies in Subjects With Advanced Gastrointestinal, Biliary Tract, or Pancreatic Cancers With…
Amgen Inc. - A Trial to Learn if Fianlimab and Cemiplimab Are Safe and Work Better Than Anti-PD1 Alone in Adult Participants With Resectable Stage 3 or 4 Melanoma
Regeneron Pharmaceuticals, Inc. · Active, not recruiting · NCT06190951 - A Phase 3 Randomized, Double Blind Study of Pembrolizumab Plus Gemcitabine,Cisplatin versus Placebo Plus Gemcitabine,Cisplatin as First-Line Therapy in Participants with Advanced and,or Unresectable Biliary Tract Carc…
Merck Sharp & Dohme LLC - Ph iii study to evaluate the efficacy and safety of astegolimab in copd
Genentech, Inc.
From CMS Open Payments research payments, where companies name up to five principal investigators per payment. Research payments usually go to hospitals, universities and research sites, not to the investigator personally. A payment is not evidence of wrongdoing.